Many devices could benefit from an active layer having a network of regularly interconnected nanometer scale pores, including optoelectronic devices (e.g. photovoltaic cells, organic LEDs, and lasers), optical devices (e.g. waveguides and optical filters), mechanical devices (e.g. filters and separation media), and chemically-active devices (e.g. catalysts. In each of these and other device applications, it would be beneficial to have a nanometer-scale network comprised of either semiconducting (e.g. semiconducting metal oxides), conducting materials (e.g. metals), and/or sequentially placed conformal layers of semiconducting and conducting materials as a component of such devices.
Recently, mesoporous templates have been fabricated using sol gel surfactant temptation techniques. Examples of such surfactant-templation techniques for producing porous films are described, e.g., by Brinker, et al in U.S. Pat. No. 6,270,846, the disclosures of which are incorporated herein by reference. Such sol gel techniques can fabricate mesoporous metal oxide templates, which can be semiconducting. However, templates fabricated in this fashion often have an irregular pore structure with undulating channels as illustrated schematically in FIG. 1. The undulating channels make it difficult to incorporate material. Further, the types of metal oxides which can be formed using sol gel techniques are limited. In addition, conducting metal materials cannot be formed using sol gel techniques.
Sol gel techniques can fabricate silica templates with straight channels that intersect at right angles, as depicted schematically in FIG. 2. Unfortunately, silica is highly insulating and therefore not suitable as a semiconducting or conducting material. Furthermore, even the pore structure of FIG. 2 is difficult to fill or coat. Specifically, there is no satisfactory way to uniformly deposit material in both the horizontal pores as well as the vertical pores.
Thus, there is a need in the art, for a device containing regularly interconnected nanometer scale pores that are uniformly coated on their surface that overcomes the above difficulties and a corresponding method for making such a device.